16,311 research outputs found
Fluid pressure balanced seal
A seal which increases in effectiveness with increasing pressure is presented. The seal's functional capability throughout both static and dynamic operation makes it particularly useful for sealing ball valve ports. Other features of the seal include the ability to seal two opposed surfaces simultaneously, tolerance of small misalignments, tolerance of wide temperature ranges, ability to maintain positive sealing contact under conditions of internal or external pressurization, and ability to conform to slight irregularities in seal or surface contours
Oil and fat absorbing polymers
A method is described for forming a solid network polymer having a minimal amount of crosslinking for use in absorbing fats and oils. The polymer remains solid at a swelling ratio in oil or fat of at least ten and provides an oil absorption greater than 900 weight percent
Polymers used to absorb fats and oils: A concept
One approach to problem of excessive oils and fats is to develop method by which oil is absorbed into solid mixture for elimination as solid waste. Materials proposed for these purposes are cross-linked (network) polymers that have high affinity for aliphatic substances, i. e., petroleum, animal, and vegetable oils
Geologic utility of improved orbital measurement capabilities in reference to non-renewable resources
Spectral and spatial characteristics necessary for future orbital remote sensing systems are defined. The conclusions are based on the past decade of experience in exploring for non-renewable resources with reference to data from ground, aircraft, and orbital systems. Two principle areas of investigation are used in the discussion: a structural interpretation in a basin area for hydrocarbon exploration, and a discrimination of altered areas in the Cuprite district in Nevada
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Service of process in the United States under Insolvency Rule 12.12
Explains the procedure to be followed by a UK based liquidator wishing to serve insolvency proceedings on parties based in the US under the Insolvency Rules 1986 r.12.12. Discusses the rule's requirements for obtaining leave of the court for service outside the jurisdiction, the court's discretion to order the manner of service, including the approach of the Chancery Division in Re Busytoday Ltd, and the obligations imposed by the Hague Convention on the Service Abroad of Judicial and Extrajudicial Documents in Civil or Commercial Matters 1965. Evaluates the methods of service authorised by the Convention and details the main elements involved in service by the Central Authority route or by a local process server
Solid propellant motor
A case bonded end burning solid propellant rocket motor is described. A propellant with sufficiently low modulus to avoid chamber buckling on cooling from cure and sufficiently high elongation to sustain the stresses induced without cracking is used. The propellant is zone cured within the motor case at high pressures equal to or approaching the pressure at which the motor will operate during combustion. A solid propellant motor with a burning time long enough that its spacecraft would be limited to a maximum acceleration of less than 1 g is provided by one version of the case bonded end burning solid propellant motor of the invention
THz Repetition Frequency Mode-Locked Laser Using Novel Sampled Gratings
Conventional sampled grating distributed-Bragg-gratings (C-SGDBRs) are widely used in tunable DBR lasers [1], and more recently have been used to precisely control the wavelength spacing in arrays of DBR lasers for use in WDM systems [2], and as the reflectors in THz repetition frequency (Fr) semiconductor mode locked lasers (SMLLs) [3]. However, the effective coupling coefficient, κ, of a C-SGDBR (Fig. 1(a)) is necessarily reduced substantially from that of a uniform grating because much of the sampled grating period has no grating. Here, for the first time, we apply a combination of π-phase shifted gratings, previously demonstrated in fiber lasers [4], with the C-SGDBR technique to THz repetition frequency SMLLs. Using a single electron beam lithography (EBL) step we have demonstrated a 620 GHz side-wall SGDBR MLL with an increased effective κ
Integrated Phase-locked Laser Diodes at 1.55μm
Two types of integrated phased locked laser diodes operating at 1.55 μm were demonstrated, using either a distributed feedback laser seeding source or a self-locking multi-mode interference array. Both exhibited far field patterns that reflected mutual coherence between the light from the output waveguides
Dynamic modal analysis of monolithic mode-locked semiconductor lasers
We analyze the advantages and applicability limits of the mode-coupling approach to active, passive, hybrid, and harmonic mode-locking in diode lasers. A simple, computationally efficient numerical model is proposed and applied to several traditional and advanced laser constructions and regimes, including high-frequency pulse emission by symmetric and asymmetric colliding pulse mode-locking, and locking properties of hybrid modelocked Fabry–Perot and distributed Bragg reflector lasers
Improvement of indoor VLC network downlink scheduling and resource allocation
Indoor visible light communications (VLC) combines illumination and communication by utilizing the high-modulation-speed of LEDs. VLC is anticipated to be complementary to radio frequency communications and an important part of next generation heterogeneous networks. In order to make the maximum use of VLC technology in a networking environment, we need to expand existing research from studies of traditional point-to-point links to encompass scheduling and resource allocation related to multi-user scenarios. This work aims to maximize the downlink throughput of an indoor VLC network, while taking both user fairness and time latency into consideration. Inter-user interference is eliminated by appropriately allocating LEDs to users with the aid of graph theory. A three-term priority factor model is derived and is shown to improve the throughput performance of the network scheduling scheme over those previously reported. Simulations of VLC downlink scheduling have been performed under proportional fairness scheduling principles where our newly formulated priority factor model has been applied. The downlink throughput is improved by 19.6% compared to previous two-term priority models, while achieving similar fairness and latency performance. When the number of users grows larger, the three-term priority model indicates an improvement in Fairness performance compared to two-term priority model scheduling
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